This invention relates to apparatus for injecting plants, principally trees, with therapeutic liquid compositions; more particularly, it relates to such apparatus which incorporate a two-component, telescopically compressible, pressure generating, fluid container having an improved sealing mechanism for negating fluid leakage between closely fitting telescopic portions of the container walls. The improved sealing mechanism provides for enhanced safety in the shipping and handling of therapeutic liquid compositions including toxic liquid materials.
The treatment of plants, especially trees, through the injection of liquid nutrients and pest control agents has been practiced for some time. In particular, a method and apparatus for such treatment is described in U.S. Pat. No. 3,286,401 to Mauget wherein a sealed container comprising two mutually slideable cups with spaced interlocks is adapted to be employed in combination with a feeder tube that is driven into the trunk of a tree to be injected.
The slideable cups of Mauget provide a variable volume container in which sealing of the interior fluid reservoir is effected by means of interference fits between the concentric, smooth walls of the cup-like members of which it is assembled. Under most conditions, a suitable and reliable seal is attained by this structural arrangement. However, in some circumstances, small variations (a) in the concentricity of the cups, (b) in the physical dimensions of the container halves, and (c) in expansion and contraction induced by atmospheric conditions, as well as imperfections arising from surface scratches, can permit the discharge between the mutually slideable walls of at least a portion of the liquid contents of the container during shipment or storage. Such leakage is especially likely to occur with liquid contents showing a high affinity for forming capillary films.
Since the liquid compositions which are adapted for use in plant injection apparatus employing telescopic-type containers include insecticides and fungicides which may be toxic or otherwise harmful, the probability of leakage between the telescopic wall portions of such containers must be reduced or eliminated.
Accordingly, an object of this invention is to provide a two-component telescopically compressible, hollow container for plant injectable fluid compositions which includes an improved hermetic sealing mechanism for interdicting capillary or other type of fluid leakage between closely fitting telescopic portions of the container walls.
Another object of this invention is to provide two-component telescopically compressible, hermetically sealed, hollow containers for plant injectable fluid compositions wherein hermetic sealing is effected by the juxtaposition of relatively minute, concentric ridges extending between mating faces of interfitting, telescopically slideable, cup-like members forming a sealed container.